1. Field of the Invention
The present invention relates to a method and apparatus for use in drying and harvesting vine borne crops and more particularly to such a method and apparatus which achieve conspicuous success to a degree not heretofore possible, in the drying of grapes on their vines to form raisins and in the subsequent harvesting of the raisins from the vines and which possess marked advantages in the application of fluids to crops for other purposes.
2. Description of the Prior Art
Proper horticultural practice calls for the periodic application of fluids of a variety of types to plant life and their crops to prevent infestation with pests, to prevent or eradicate diseases, to achieve thinning of the crop and the like. The use of selected fluids has also been employed experimentally for more specific applications. For example, it has been known that grapes can be dried on the vine to form raisins by spraying the grapes with a solution such as potassium carbonate and methyl oleate to initiate the dehydration process. Such a solution acts greatly to reduce or to eliminate the insulating effect of the wax-like coating on the individual grapes and permits them to be dried relatively quickly on the vine by ambient temperatures and sunlight. In order to be effective, the process requires thorough coverage of the individual berries of the grapes with the solution and, thereafter, servering of selected canes of the vines. Only those canes are severed which are necessary to interrupt the flow of nutrients to the grapes thus preserving other canes to be used in the subsequent year for the bearing of crops. This severing or pruning step accelerates the drying process and reduces abscission between the raisins and their stems.
Heretofore, this process has not achieved wide usage because of severe practical difficulties. For example, complete application of the solution to the grapes is rendered difficult or impossible by the enveloping foliage of the grapevines and by the fact that grapevines trained and grown in the conventional fashion support the grapes at widely spaced elevations within the surrounding foliage. Thus, when the solution which initiates the dehydration process is sprayed on the vines by a conventional automated device, the spray is prevented from reaching much of the crop. Consequently, uneven and inadequate drying occurs unless manual direction of the spraying fluids is provided. Such manual augmentation and assistance is inefficient and largely impractical. The result has been that the vine drying of grapes has not achieved wide usage although the advantages in the use of the process, such as minimizing crop damage due to irregularities in the weather and the capability of waiting until the optimum state of development of the grapes for drying and harvesting, have long been recognized.
Therefore, it has long been known that it would be desirable to provide a method and apparatus for use in drying and harvesting vine borne crops and performing other work operations which have particular utility in the vine drying of grapes to form raisins wherein the solution employed to initiate the dehydration process is applied automatically achieving thorough and virtually complete application to the grapes and the raisins so formed can be harvested using the same apparatus operated on a fully automated basis.